Mites are the one thing I just don't want to deal with....and it's not an uncommon problem with growing marijuana. What I have found works for me, in my area, is to wait until the Fall to start my seeds. That way, it's less likely that pests will be vectored into the grow space from outside -as they are going dormant in the cooler weather. As you mentioned, mites are very small and they can "ride" into your grow room via you, your pets, your kids, open windows, etc. Your first line of defense is to make your space and anything entering into it, surgically clean. Your second line of defense is to carefully observe your plants with a magnifying glass everyday and be on top of anything that sneaks up.
Once the mites have become established, there's not much you can do, tbh. It's not just about finding a way to kill the living mites, but also about considering all the poop, eggs, webs and corpses of the ones you kill. It all stays on the plant. You're left with few options. Bud washing will diminish some of the garbage, but it won't do anything to the webs. And bud washing is an art unto itself that can cause even more problems if it's not done meticulously. I'm not sure how extensive your mite problem is, but sometimes, you just have to cut your losses and chalk it up to a lesson learned to do better next time.
On the other hand, when I was young and weed was illegal and scarce, I smoked many a mite and probably other bugs and whatever other "crap" was on the plants. I just didn't care. Sad, but true.
Someone once said that growing weed was easy. It is. But, growing the best quality marijuana for consumption, is a whole other story.
